The vulnerability in OpenRemote's UserResourceImpl class arises because three read methods (get, getUserClientRoles, getUserRealmRoles) check only for the read:admin role but do not verify that the target user belongs to the caller's realm. The realm path parameter is accepted but not used to restrict access. This allows a realm admin from one tenant realm to query user details from any other realm, including the master realm, by using the target user's UUID. Write methods in the same class enforce realm boundaries properly, indicating an omission in the read methods. The vulnerability enables cross-realm user information disclosure and privilege reconnaissance in multi-tenant deployments. A proof of concept demonstrates that a tenantb realm admin can retrieve the master realm administrator's profile and roles using the REST API. The affected versions are all versions before 1.24.2. There is no evidence of known exploits in the wild or an official patch available at this time.

An attacker with realm-admin-level privileges in one tenant can enumerate and read sensitive user information, including profiles and roles, of users in other realms, including the master realm. This breaks tenant isolation in multi-tenant deployments, potentially exposing privileged account details and enabling further privilege escalation or reconnaissance. The vulnerability does not affect integrity or availability directly but compromises confidentiality of user data across realms.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict realm-admin privileges carefully and monitor access to the affected API endpoints. Consider compensating controls such as network segmentation or additional access controls to limit cross-realm API calls. Avoid sharing UUIDs of privileged users across tenants to reduce risk of targeted enumeration.